The invention relates to a pistol including a device configured to determine the number of shots fired.
Pistols supposedly capable of determining the shots fired are known (DE 39 11 804 C2 and U.S. Pat. No. 4,541,191). Since the piezoelectric sensor disclosed in these references can also be subjected to other mechanical impulses, for example, when the pistol is dropped or during firing of practice rounds due to the lock or firing-pin movement during a simulated discharge, the counting of shots fired from these pistols is flawed. In order to avoid such errors, DE 40 22 038 discloses a device having three direction and acceleration dependent sensors instead of a single sensor. DE 44 17 545 A1 discloses several sensors located in the front of the pistol muzzle configured to detect a bullet as it is flying by.
The purpose of the present invention is to provide a cost efficient pistol having a reliable device configured to determine the number of shots. This objective is achieved by the pistol disclosed herein. Further advantageous developments of the invention are also disclosed herein.
According to the present invention, the device for determining the number of shots fired by the pistol includes a piezoelectric first sensor and a second sensor. The piezoelectric sensor transmits a first signal to a microprocessor upon receipt of a mechanical impulse. The second sensor is activated when the carriage slides back during a discharge. The time interval between the first signal produced by the piezoelectric sensor and the second signal produced by the second sensor is compared by the microprocessor. The compared time interval is that between the first signal, produced as a result of the recoil impulse during a live shot, and the second signal, produced when the carriage slides back during a live shot. When the time interval is positive a count impulse is stored. When a live shot is fired, the time interval between the first and the second signals is around a few milliseconds.
A battery can be provided as the current supply. Preferably, current is supplied for storage of the data received and for operation of a real-time clock discussed below.
The remaining electronics, including the second sensor, are only supplied with current after the first sensor is activated. Thus, the first signal, produced by the piezoelectric sensor, serves at the same time as an activation signal for the electronics. The time interval for activating the microprocessor and the other connected electronics is usually a few microseconds.
If necessary, the piezoelectric sensor can be a common ceramic piezoelement. However, the piezoelectric sensor is preferably formed by a piezoelectric polymer sensor or piezofilm sensor, preferably out of fluoropolymers, in particular polyvinylidenefluoride (PVDF) and copolymers of PVDF. The piezofilm sensor consists of a piezofilm piece or a small plate, having an electric layer on each side, such as a metal layer, like silver. The electrode layers are connected to the microprocessor. Each electrode layer can have a protective outer coating.
The piezofilm sensor can be attached to any desired area of the pistol handle since the recoil impulse deforms practically the entire handle during discharge. The piezofilm sensor is advantageously arranged on a printed circuit board which also houses the electronics.
The circuit board is preferably designed as a multilayer printed circuit board. The circuit board is preferably positioned on the section of the handle between the trigger and the barrel muzzle under the carriage. The piezofilm sensor can then be arranged on the side of the circuit board opposite the carriage and can be positioned between two layers of the circuit board.
The second sensor can be designed differently than the first sensor. The second sensor can also be constructed by a piezoelectric sensor, in particular a piezofilm sensor, which is deformed by the carriage when the carriage slides back during discharge. In this instance, a nose or similar projection of the carriage will operate the piezosensor when the carriage slides back. Alternatively, if the second sensor is formed by an induction coil, a permanent magnet 27 (FIG. 1) could be positioned on the carriage.
The second sensor is preferably a coil which is supplied with current from a frequency generator. Since the carriage of the pistol consists of metal, the sensor coil is damped when a section of the carriage slides back past the coil. The oscillation amplitude reduced by damping is transmitted as a signal to the microprocessor. The section of the carriage which moves past the sensor coil can, for example, be the front face wall of the carriage. The sensor coil is preferably arranged on the side of the printed circuit board facing the carriage in order to achieve the most significant damping.
In order for the device to determine the time of firing each shot, in addition to the number of shots fired, a real-time clock is also provided on the printed circuit board. Thus, since the time of firing of a shot is recorded with each fired shot based on a reading from the real-time clock the pistol can record each firing event.
A read-out of the stored data on the pistol handle can be accomplished through a cable or contacts. Preferably the read-out does not require contacts since the pistol handle will generally consist of plastic. Thus, it is preferable to provide an RF transmitter in the pistol handle which communicates with an RF receiver as the reading device outside of the pistol. In order for the microprocessor to be programmable from outside and in order for data to be read into storage, the RF transmitter in the pistol handle is also preferably an RF receiver.
The RF transmitter and, if necessary, receiver, in the pistol handle is/are preferably arranged on the printed circuit board. The antenna for the transmitter/receiver is preferably an antenna coil and is positioned on the side of the printed circuit board opposite the carriage.
The device also includes a reading device which can be designed as a hand-held reading device. The reading device can also be configured for connection to a personal computer or laptop.
The device of the present invention can also be configured to determine further characteristic data of the pistol. The characteristic data can include data for identification of the pistol and/or data regarding the owner of the pistol, which is read into storage.
For the programming and reading-in of the characteristic data, a recording device 26 (FIG. 1) outside of the pistol can be used. The recording device can be an RF transmitter which is connected to a personal computer or laptop. The recording device can also be designed as a reading device.
The pistol identification data could include the number of the weapon, which is also applied to the weapon. The pistol identification data could also include data such as the production date of the pistol, the charge number of the pistol, etc. A recording device could be installed at the production site to input this data. The pistol ownership data read into storage could include the name of the legal owner of the weapon. The name could be read into storage via a recording device by the seller when the pistol is purchased. The data could also be read in by a public authority or similar institution. In addition, if the ownership of the pistol changes, the legal name of the new owner could be read into storage.